This invention relates to electrical connectors, and particularly to an electrical jumper for electrically connecting two or more adjacent pins which extend from electronic devices.
Printed circuit boards are typically provided with a row or array of pins (a "pin field") to facilitate making connections between the electronic components on the board and external devices including other printed circuit boards. Electronic equipment, including digital computers, may also be provided with such pin fields for connecting the equipment to peripheral devices or data communication lines.
If a printed circuit board is capable of several uses, the devices which can be connected to its pin field may vary. This is almost certainly the case with a pin field of a general purpose device such as a digital computer. For some applications, it may be necessary to "jump", or electrically interconnect, two or more pins in the pin field. The jumped pins may or may not have further connections made to them.
It is therefore known to provide jumpers which can interconnect two or more pins in a pin field. The jumpers are generally rectangular and of such dimensions that there is sufficient space to connect additional jumpers on adjacent pins. The jumpers have an entry end with apertures for the entry of the pins, and are generally shorter than the pins so that the pins protrude from the opposite, exit end of the jumper to allow additional connections to be made to them. Because of their small dimensions, these jumpers are sometimes called "low profile" jumpers.
Such jumpers have a housing made of a non-conductive, dielectric material, having electrically interconnected terminals for receiving the pins to be jumped. It is known to provide electrically interconnected terminals by forming the entire terminal member from one piece of conductive material, by stamping or otherwise. A conductive material commonly used in a metal, such as hard phosphor bronze, plated with nickel, then overplated with gold or a tin/lead alloy.
In one particular known type of jumper for interconnecting two pins, the terminal member has four arms, two for engaging each pin. Each pair of arms engages its respective pin from two sides. Each arm is provided with a dimple for better contact with its respective pin. The arms extend from a central spine, which is received in a slot in the housing, across to the sides of the housing. The free ends of the arms are supported in slots in the sides of the housing.
This known type of jumper functions well, but is not easily assembled automatically at high speeds. The free ends of the arms of the terminal member are sometimes bent out of place before the terminal member is inserted into the housing, so that they do not align properly with the slots intended to receive them. Alternatively, the arms may bend in the slots if accumulated tolerances are such that a maximum width arm is mated to a minimum width slot. As a result, the arms bend instead of seating properly in the slots. Such a jumper must then be discarded. Therefore, this type of jumper is assembled by hand.
In addition, when forming the dimples in the arms of the known jumper, if the metal which is used for the terminal member has been plated before the dimples are formed ("pre-plated"), there is a tendency for the base metal to break through the plating when the dimple is formed. Therefore, the terminal members of the known jumper are plated after they are formed. Such post-plating is a more difficult and expensive step than pre-plating.
Jumpers of the types generally described above can be provided in multiple units which allow discrete pairs of pins to be electrically connected by a number of electrically isolated terminal members in a common housing. In addition, jumpers can be provided which interconnect a multiplicity of pins in a bus bar configuration.